For what it's worth, I got very positive post-interview stuff from MGH and matched there, but also got very positive stuff from UCSF, which was my number one, and didn't match there. They sent me emails, told a current resident "if she wants to come here, she can...". While I didn't get an explicit "you are ranked to match" comment, I definitely felt like they gave me the impression a spot was mine for the taking, which it clearly was not.
So the moral of the story is, trust no one. All that post-interview contact SHOULD be outlawed, I think. Because what benefit is it to us? None. All it can do is sway you towards a program that you think "wants" you. What benefit is it to the program? Significant, because if they recruit everyone heavily, then they can say they went less far down their match list. My thought is, each program should have the cajones to rank who they want in the order they want them, period. If they have to go far down their match list, maybe that should be a sign they need to work on things, rather than a sign they didn't "play the game" well enough.
Just my unsolicited two cents on this one...